Unable to activate iPhone 7

Hi all,

Having recently updated my iphone to IOS 13.3 I now cannot make or receive calls or connect to mobile data. I have followed all the advice online and connected my phone to my itunes to try and update it but every time it keeps telling me that an update is required.

Nearing the end of my patience I factory reset my phone and it is nothing more than a piece of aluminium and glass as it now wont activate. When I go through the stages of manual set up Im getting the message " Unable to Activate! An update is required to activate you iPhone" and a blue shutdown bar.

I have tried everything suggested on the apple support pages but nothing has worked.

Can anyone please help me or point me in the right direction with this before this iphone ends up at the bottom of a lake?

Many thanks, David